Happy Leap Day to all!
As you probably already know, a normal year is about 365 days because that is how long it takes Earth to complete one trip around the sun (though this may seem a bit slow, we’re actually traveling at a blistering pace of around 67,000 miles per hour). However, 365 days isn’t entirely accurate….it actually takes about 365.25 days to make the journey. Around 45 B.C. Julius Caesar very wisely decided that every four years we’d add an extra day to the calendar to prevent us from getting way behind, instead of having one day each year that was only a few hours long. Though the ancient Romans didn’t quite have the equipment to observe and make these calculations as accurately as we do today, Caesar had a talented astronomer, Sosigenes, in his employ that was able to calculate all of this using some very complicated math.
Did You Know? Though the leap day occurring every four years is common knowledge, less is known about the leap year changes that happen every four centuries. Though the actual time it takes Earth to make one revolution around the sun is very close to 365.25, it’s not quite exact. Because of this, every 300 years we skip a leap year (if we didn’t, we’d be about a week ahead of what day it actually is by now). But don’t worry, it’s not something we’ll have to remember any time soon—the next skipped leap year won’t happen until the year 2300!